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J/AJ/106/56 HII regions in NGC 6814 (Knapen+, 1993)
Statistics and properties of HII regions in NGC 6814
KNAPEN J.H., ARNTH-JENSEN N., CEPA J., BECKMAN J.E.
<Astron. J. 106, 56 (1993)>
=1993AJ....106...56K (SIMBAD/NED Reference)
ADC_Keywords: Galaxies, optical; H II regions; Positional data
Abstract:
We present a new Halpha image of high quality of the grand-design
galaxy NGC 6814, and describe statistical properties of the HII region
population. We have determined positions, angular sizes, and
calibrated fluxes of 735 individual HII regions. We construct
luminosity functions (LFs) for the complete sample, separately for arm
and interarm regions, and for HII regions within and outside the
limiting radius corresponding to the bright optical disk. The slope of
the LF for the complete sample agrees well with values published for
other Sbc and Sc galaxies. LFs for HII regions in the arms, in the
interarm regions, in the inner part, and in the outer part of the
galaxy all have the same slopes. We show and discuss the diameter
distribution of the HII regions, both for the complete sample and for
the separate arm, interarm, inner, and outer disk samples. There is no
evidence for a different population of HII regions in the spiral arms,
nor is there evidence for the existence of a significant population of
density-bounded HII regions. We discuss implications for massive star
forming processes in this galaxy, and discuss possible differences from
other grand-design spirals.
File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file
table 48 735 HII regions. This table lists the 735 HII
regions catalogued in the disk of the
grand-design spiral galaxy NGC 6814, using
a new H alpha image. The center is also
included in the list.
Byte-by-byte Description of file: table
Bytes Format Units Label Explanations
1- 3 I3 --- ID Identification number of the HII region.
HII regions closely grouped in the galaxy
have generally closely grouped numbers.
5- 12 F8.2 arcsec dRA Right ascension offset from the nucleus. Not
corrected for inclination of the galaxy.
13- 20 F8.2 arcsec dDE Declination offset from the nucleus.
21- 27 F7.1 arcsec Dist Deprojected distance from the center. An
inclination angle of 20 degrees and a
position angle of PA=167 degrees were used
for the deprojection.
28- 34 F7.2 arcsec DHII Diameter of the HII region
35- 45 F11.4 [10-7J/s] log(LHII) HII region total integrated luminosity
48 A1 --- THII [CAIO] Type assigment given to the
HII region. See note (1)
--------------------------------------------------------------------------------
Note (1)
C: center (not an HII region, but included for comparison)
A: Arm HII region
I: interarm
O: outer HII region
An outer HII region is defined as lying outside the area of the strong
spiral arms, d>43 arcsec or 0.4 R25.
Origin: AAS CD-ROM series, Volume 1, 1993
(End) Patricia Bauer [CDS] 25-Jul-1994